Person:
Leite Fernandes, Vitor Samuel

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First Name
Vitor Samuel
Last Name
Leite Fernandes
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Fisiología
Area
Fisiología
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Now showing 1 - 7 of 7
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    Neuronal and non-neuronal bradykinin receptors are involved in the contraction and/or relaxation to the pig bladder neck smooth muscle
    (Neurourology and urodynamics, 2013) Ribeiro, Ana Sofía Fernandes; Leite Fernandes, Vitor Samuel; Martínez Sainz, María Del Pilar; Martínez-Sáenz, Ana; Pazos Rodríguez, María Ruth; Orensanz Muñoz, Luis Miguel; Recio Visedo, María Paz; Bustamante Alarma, Salvador; Carballido Rodríguez, Joaquín; García Sacristán, Albino; Prieto Ocejo, Dolores; Hernández Rodríguez, Medardo Vicente
    Aims: The current study investigates the role played by bradykinin (BK) receptors in the contractility to the pig bladder neck smooth muscle. Methods: Bladder neck strips were mounted in myographs for isometric force recordings and BK receptors expression was also determined by immunohistochemistry. Results: B2 receptor expression was observed in the muscular layer and urothelium whereas B1 expression was consistent detected in urothelium. A strong B2 immunoreactivity was also observed within nerve fibers among smooth muscle bundles. On urothelium-denuded preparations basal tone, BK induced concentration-dependent contractions which were reduced in urothelium-intact samples, by extracellular Ca(2+) removal and by blockade of B2 receptors and voltage-gated Ca(2+) (VOC) and non-VOC channels, and increased by cyclooxygenase (COX) inhibition. On phenylephrine-precontracted denuded strips, under non-adrenergic non-cholinergic (NANC) conditions, electrical field stimulation-elicited frequency-dependent relaxations which were reduced by B2 receptor blockade. In urothelium-intact samples, the B1 receptor agonist kallidin promoted concentration-dependent relaxations which were reduced by blockade of B1 receptors, COX, COX-1 and large-conductance Ca(2+) -activated K(+) (BKCa ) channels and abolished in urothelium-denuded samples and in K(+) -enriched physiological saline solution-precontracted strips. Conclusions: These results suggest that BK produces contraction of pig bladder neck via smooth muscle B2 receptors coupled to extracellular Ca(2+) entry via VOC and non-VOC channels with a minor role for intracellular Ca(2+) mobilization. Facilitatory neuronal B2 receptors modulating NANC inhibitory neurotransmission and urothelial B1 receptors producing relaxation via the COX-1 pathway and BKCa channel opening are also demonstrated.
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    Project number: 407
    Autoevaluación, Coevaluación y el uso de las TIC como enfoque innovador en las prácticas de Fisiopatología y su efecto en el proceso de enseñanza-aprendizaje del alumno
    (2023) Leite Fernandes, Vitor Samuel; Agis Torres, Ángel; Benedito Castellote, Sara; Climent Flórez, Belén; Contreras Jiménez, Cristina; García Sacristán, Albino; Gómez del Val, Alfonso; Hernández Rodríguez, Medardo Vicente; Hernández Martín, Marina; López-Oliva Muñoz, María Elvira; Merino Martín, José Joaquín; Montenegro Álvarez De Tejera, María Pilar; Muñoz Picos, Mercedes; Navarro Dorado, Jorge; Pascual Gómez, Natalia Fernanda; Perales Calvo, Manuel; Prieto Ocejo, Dolores; Puente Maya, Francisco Jesus; Raposo González, Rafaela; Recio Visedo, María Paz; Rivera De Los Arcos, Luis; Sánchez Pina, Ana Alejandra
    En las últimas décadas, la educación universitaria ha evolucionado hacia un enfoque constructivista en consonancia con las recomendaciones del Espacio Europeo de Educación Superior (EEES). En este paradigma, los estudiantes asumen un papel activo en el proceso de enseñanza-aprendizaje, mientras los profesores actúan como facilitadores. Las metodologías constructivistas fomentan el desarrollo tanto individual como grupal de competencias específicas y genéricas, al tiempo que permiten la inclusión de agentes de evaluación formativa para estimular la crítica y la autocrítica del alumno en su desempeño. En este contexto, surge la necesidad de aplicar el constructivismo a la evaluación, involucrando al estudiante en su propio proceso de evaluación. La autoevaluación y la coevaluación emergen como alternativas concretas para lograrlo. La autoevaluación implica que el estudiante analice y valore de manera sistemática su trabajo durante el proceso de aprendizaje para mejorar resultados y fomentar la autocrítica. Por otro lado, la coevaluación es una evaluación entre compañeros que permite valorar la implicación y actitud de los miembros del grupo, estimulando el aprendizaje colectivo. Las Tecnologías de la Información y Comunicación (TIC) juegan un papel importante en la educación y en la evaluación de los alumnos, diferenciándose de las prácticas tradicionales. La implementación de TIC no solo desarrolla habilidades en el proceso enseñanza-aprendizaje, sino también favorece la autoevaluación y la coevaluación. Con base en este enfoque, se presenta un proyecto de innovación docente en la asignatura de Fisiopatología para estudiantes de Farmacia. Los alumnos crearán videos sobre temas específicos de la práctica y se evaluarán a sí mismos y a sus compañeros utilizando la herramienta App Plickers. Sin embargo, aún no existe una metodología claramente definida para la implementación de estrategias constructivistas y uso de TIC en Fisiopatología, destacando la importancia y relevancia de este proyecto.
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    Endogenous Hydrogen Sulfide has a Powerful Role in Inhibitory Neurotransmission to the Pig Bladder Neck
    (Journal of Urology, 2013) Leite Fernandes, Vitor Samuel; Ribeiro, Ana S.F.; Martínez, María Pilar; Orensanz, Luis M.; Barahona Gomáriz, María Victoria; Martínez-Sáenz, Ana; Recio Visedo, María Paz; Benedito Castellote, Sara; Bustamante, Salvador; Carballido, Joaquín; García Sacristán, Albino; Prieto Ocejo, Dolores; Hernández Rodríguez, Medardo Vicente
    Purpose: We investigated the possible involvement of H2S in nitric oxide independent inhibitory neurotransmission to the pig bladder neck. Materials and methods: We used immunohistochemistry to determine the expression of the H2S synthesis enzymes cystathionine γ-lyase and cystathionine β-synthase. We also used electrical field stimulation and myographs for isometric force recordings to study relaxation in response to endogenously released or exogenously applied H2S in urothelium denuded, phenylephrine precontracted bladder neck strips under noradrenergic, noncholinergic, nonnitrergic conditions. Results: Cystathionine γ-lyase and cystathionine β-synthase expression was observed in nerve fibers in the smooth muscle layer. Cystathionine γ-lyase and cystathionine β-synthase immunoreactive fibers were also identified around the small arteries supplying the bladder neck. Electrical field stimulation (2 to 16 Hz) evoked frequency dependent relaxation, which was decreased by DL-propargylglycine and abolished by tetrodotoxin (blockers of cystathionine γ-lyase and neuronal voltage gated Na(+) channels, respectively). The cystathionine β-synthase inhibitor O-(carboxymethyl)hydroxylamine did not change nerve mediated responses. The H2S donor GYY4137 (0.1 nM to 10 μM) induced potent, concentration dependent relaxation, which was not modified by neuronal voltage gated Na(+) channels, or cystathionine γ-lyase or cystathionine β-synthase blockade. Conclusions: Results suggest that endogenous H2S synthesized by cystathionine γ-lyase and released from intramural nerves acts as a powerful signaling molecule in nitric oxide independent inhibitory transmission to the pig bladder neck.
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    Bladder Dysfunction in an Obese Zucker Rat: The Role of TRPA1 Channels, Oxidative Stress, and Hydrogen Sulfide
    (2019) Blaha, Igor; López-Oliva Muñoz, María Elvira; Martínez Sainz, María Del Pilar; Recio Visedo, María Paz; Agis Torres, Ángel; Martínez Gómez, Ana Cristina; Benedito Castellote, Sara; García Sacristán, Albino; Leite Fernandes, Vitor Samuel; Prieto Ocejo, Dolores; Hernández Rodríguez, Medardo Vicente
    Purpose: This study investigates whether functionality and/or expression changes of transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) channels, oxidative stress, and hydrogen sulfide (H2S) are involved in the bladder dysfunction from an insulin-resistant obese Zucker rat (OZR). Materials and methods: Detrusor smooth muscle (DSM) samples from the OZR and their respective controls, a lean Zucker rat (LZR), were processed for immunohistochemistry for studying the expression of TRPA1 and TRPV1 and the H2S synthase cystathionine beta-synthase (CBS) and cysthathionine-γ-lyase (CSE). Isometric force recordings to assess the effects of TRPA1 agonists and antagonists on DSM contractility and measurement of oxidative stress and H2S production were also performed. Results: Neuronal TRPA1 expression was increased in the OZR bladder. Electrical field stimulation- (EFS-) elicited contraction was reduced in the OZR bladder. In both LZR and OZR, TRPA1 activation failed to modify DSM basal tension but enhanced EFS contraction; this response is inhibited by the TRPA1 blockade. In the OZR bladder, reactive oxygen species, malondialdehyde, and protein carbonyl contents were increased and antioxidant enzyme activities (superoxide dismutase, catalase, GR, and GPx) were diminished. CSE expression and CSE-generated H2S production were also reduced in the OZR. Both TRPV1 and CBS expressions were not changed in the OZR. Conclusions: These results suggest that an increased expression and functionality of TRPA1, an augmented oxidative stress, and a downregulation of the CSE/H2S pathway are involved in the impairment of nerve-evoked DSM contraction from the OZR.
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    Project number: 349
    Adaptación a un entorno semipresencial de una nueva herramienta mixta del aprendizaje basado en problemas en combinación con las prácticas de laboratorio clínico a la nueva asignatura Bases Anatómicas y Fisiología del Cuerpo Humano
    (2021) Muñoz Picos, Mercedes; Agis Torres, Ángel; Benedito Castellote, Sara; Bragado Aguado, María del Carmen; Climent Flórez, Belén; Contreras Jiménez, Cristina; García Sacristán, Albino; Gómez Del Val, Alfonso; Gutiérrez Cruz, Alejandro; Hernández Rodríguez, Medardo Vicente; Leite Fernandes, Vitor Samuel; López-Oliva Muñoz, María Elvira; Montenegro Álvarez De Tejera, María Pilar; Navarro Dorado, Jorge; Perales Calvo, Manuel; Puente Maya, Francisco Jesús; Raposo González, Rafaela; Recio Visedo, María Paz; Rivera de los Arcos, Luis; Rodríguez Prados, Claudia; Sánchez Pina, Ana Alejandra
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    Hydrogen sulfide mediated inhibitory neurotransmission to the pig bladder neck: role of KATP channels, sensory nerves and calcium signaling.
    (Journal of Urology, 2013) Leite Fernandes, Vitor Samuel; Fernandes Ribeiro, Ana Sofía; Barahona Gomáriz, María Victoria; Orensanz Muñoz, Luis Miguel; Martínez Sáenz, Ana; Recio Visedo, María Paz; Martínez Gómez, Ana Cristina; Bustamante, Salvador; Carballido, Joaquín; García Sacristán, Albino; Prieto Ocejo, Dolores; Hernández Rodríguez, Medardo Vicente
    Purpose: Because neuronal released endogenous H2S has a key role in relaxation of the bladder outflow region, we investigated the mechanisms involved in H2S dependent inhibitory neurotransmission to the pig bladder neck. Materials and methods: Bladder neck strips were mounted in myographs for isometric force recording and simultaneous measurement of intracellular Ca(2+) and tension. Results: On phenylephrine contracted preparations electrical field stimulation and the H2S donor GYY4137 evoked frequency and concentration dependent relaxation, which was reduced by desensitizing capsaicin sensitive primary afferents with capsaicin, and the blockade of adenosine 5'-triphosphate dependent K(+) channels, cyclooxygenase and cyclooxygenase-1 with glibenclamide, indomethacin and SC560, respectively. Inhibition of vanilloid, transient receptor potential A1, transient receptor potential vanilloid 1, vasoactive intestinal peptide/pituitary adenylyl cyclase-activating polypeptide and calcitonin gene-related peptide receptors with capsazepine, HC030031, AMG9810, PACAP6-38 and CGRP8-37, respectively, also decreased electrical field stimulation and GYY4137 responses. H2S relaxation was not changed by guanylyl cyclase, protein kinase A, or Ca(2+) activated or voltage gated K(+) channel inhibitors. GYY4137 inhibited the contractions induced by phenylephrine and by K(+) enriched (80 mM) physiological saline solution. To a lesser extent it decreased the phenylephrine and K(+) induced increases in intracellular Ca(2+). Conclusions: H2S produces pig bladder neck relaxation via activation of adenosine 5'-triphosphate dependent K(+) channel and by smooth muscle intracellular Ca(2+) desensitization dependent mechanisms. H2S also promotes the release of sensory neuropeptides and cyclooxygenase-1 pathway derived prostanoids from capsaicin sensitive primary afferents via transient receptor potential A1, transient receptor potential vanilloid 1 and/or related ion channel activation. Keywords: 4-AP; 4-aminopyridine; AM; ATP; ATP dependent K(+); CGRP; COX; CSE; CSPA; Ca(2+) activated K(+); Emax; K(ATP); K(Ca); K(V); KPSS; L-NOARG; MLCP; N(G)-nitro-L-arginine; NO; PACAP; PKA; PSS; TRPA(1); TRPV(1); VOC; VPAC; [Ca(2+)](i); acetoxymethyl ester; adenosine 5′-triphosphate; calcitonin gene-related peptide; capsaicin sensitive primary afferent; cyclooxygenase; cystathionine γ-lyase; hydrogen sulfide; intracellular Ca(2+); maximum response; muscle, smooth; myosin light chain phosphatase; nitric oxide; physiological saline solution; pituitary adenylyl cyclase activating polypeptide; potassium channels; potassium rich PSS; protein kinase A; synaptic transmission; transient receptor potential A1; transient receptor potential vanilloid 1; urinary bladder; vasoactive intestinal peptide receptor; voltage gated Ca(2+); voltage gated K(+).
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    Phosphodiesterase type 4 inhibition enhances nitric oxide- and hydrogen sulfide-mediated bladder neck inhibitory neurotransmission
    (Scientific Reports, 2018) Agis Torres, Ángel; Recio Visedo, María Paz; López-Oliva Muñoz, María Elvira; Martínez Sainz, María Del Pilar; Barahona Gomáriz, María Victoria; Benedito Castellote, Sara; Bustamante, Salvador; Jiménez-Cidre; Miguel Ángel; García Sacristán, Albino; Prieto Ocejo, Dolores; Leite Fernandes, Vitor Samuel; Hernández Rodríguez, Medardo Vicente
    Nitric oxide (NO) and hydrogen sulfide (H2S) play a pivotal role in nerve-mediated relaxation of the bladder outflow region. In the bladder neck, a marked phosphodiesterase type 4 (PDE4) expression has also been described and PDE4 inhibitors, as rolipram, produce smooth muscle relaxation. This study investigates the role of PDE4 isoenzyme in bladder neck gaseous inhibitory neurotransmission. We used Western blot and double immunohistochemical staining for the detection of NPP4 (PDE4) and PDE4A and organ baths for isometric force recording to roflumilast and tadalafil, PDE4 and PDE5, respectively, inhibitors in pig and human samples. Endogenous H2S production measurement and electrical field stimulation (EFS) were also performed. A rich PDE4 and PDE4A expression was observed mainly limited to nerve fibers of the smooth muscle layer of both species. Moreover, roflumilast produced a much more potent smooth muscle relaxation than that induced by tadalafil. In porcine samples, H2S generation was diminished by H2S and NO synthase inhibition and augmented by roflumilast. Relaxations elicited by EFS were potentiated by roflumilast. These results suggest that PDE4, mainly PDE4A, is mostly located within nerve fibers of the pig and human bladder neck, where roflumilast produces a powerful smooth muscle relaxation. In pig, the fact that roflumilast increases endogenous H2S production and EFS-induced relaxations suggests a modulation of PDE4 on NO- and H2S-mediated inhibitory neurotransmission.